Re: lisp/ChangeLog coding system

["Stefan Monnier" <monnier+gnu/emacs@RUM.cs.yale.edu>]

> >>>>> "Stefan" == Stefan Monnier <monnier+gnu/emacs@rum.cs.yale.edu> writes:
> 
>     >> One aspect is making better guesses about desired coding
>     >> systems.
> 
>     Stefan> I'm not sure what kind of improvements you're thinking
>     Stefan> about.
> 
> Well, in the version (mid-January, maybe?) of GNU Emacs I have, when I
> tried saving a buffer with mixed ascii, latin-1, and latin-2 in it, it
> gave me an abominably long list of coding systems including mule
> internal, all the -with-esc systems, and iso-2022-jp-2.  But all of
> the characters used in the buffer are in ISO-8859-2, it's just Mule
> making false distinctions.
> 
> At the very least, the defaults in Emacs should be to identify
> identical characters (eg, those from the Latin-## subsets) and to
> distinguish those where unification is controversial (the Han
> ideographs).

As Miles said, you can call (ucs-unify-8859 t) to unify the latin
charsets when saving a file.  Better yet: you don't need to do it any
more because it's now the default behavior.

>     Stefan> non-MIME coding-systems should be in the "unlikely" list, tho.
> 
> There is no unique "the unlikely list".
> 
> For example, if I were Croatian, I probably would want the buffer
> described above saved in ISO-8859-2 without being asked,

That's what happens right now.

> but a German
> would probably want to save it in UTF-8 (or maybe ISO-2022-7 if she
> were an Emacs developer), or be queried, defaulting to ISO-8859-2.

A German would get a prompt where iso-8859-2 and utf-8 should
be near the beginning of the list of coding-systems she can
choose from.

> And what's a "non-MIME coding system"?

I don't know.  All I know is that it's used when sorting coding-systems
so that the list has more "likely" coding systems at the beginning.
I think it's also used to choose more user-friendly names when a coding-system
has several aliases (such as mule-utf-8 and utf-8.  Don't ask me why the
coding-system is called `mule-utf-8' and why `utf-8' is only an alias, tho).

> As for most functionality being in Emacs, yes, that's why I said I'd
> help refactor; relative to ucs-tables.el the contribution is all UI.
> My duplication[1] of ucs-tables is straightforward, not terribly
> efficient code; all the meat is devoted to the question of "how do we
> know which coding systems to offer the user".  Specifically I address
> the issues of preferred unibyte systems and preferred universal
> systems described above.

I'm beginning to understand, thank you,


	Stefan